<?php

/**
 * @file
 * Administrative interface for custom field type creation.
 */

/**
 * Menu callback; lists all defined fields for quick reference.
 */
function field_ui_fields_list() {
	$instances = field_info_instances();
	$field_types = field_info_field_types();
	$bundles = field_info_bundles();

	$modules = system_rebuild_module_data();

	$header = array(t('Field name'), t('Field type'), t('Used in'));
	$rows = array();
	foreach ($instances as $entity_type => $type_bundles) {
		foreach ($type_bundles as $bundle => $bundle_instances) {
			foreach ($bundle_instances as $field_name => $instance) {
				$field = field_info_field($field_name);

				// Initialize the row if we encounter the field for the first time.
				if (!isset($rows[$field_name])) {
					$rows[$field_name]['class'] = $field['locked'] ? array('menu-disabled') : array('');
					$rows[$field_name]['data'][0] = $field['locked'] ? t('@field_name (Locked)', array('@field_name' => $field_name)) : $field_name;
					$module_name = $field_types[$field['type']]['module'];
					$rows[$field_name]['data'][1] = $field_types[$field['type']]['label'] . ' ' . t('(module: !module)', array('!module' => $modules[$module_name]->info['name']));
				}

				// Add the current instance.
				$admin_path = _field_ui_bundle_admin_path($entity_type, $bundle);
				$rows[$field_name]['data'][2][] = $admin_path ? l($bundles[$entity_type][$bundle]['label'], $admin_path . '/fields') : $bundles[$entity_type][$bundle]['label'];
			}
		}
	}
	foreach ($rows as $field_name => $cell) {
		$rows[$field_name]['data'][2] = implode(', ', $cell['data'][2]);
	}
	if (empty($rows)) {
		$output = t('No fields have been defined yet.');
	}
	else {
		// Sort rows by field name.
		ksort($rows);
		$output = theme('table', array('header' => $header, 'rows' => $rows));
	}
	return $output;
}

/**
 * Displays a message listing the inactive fields of a given bundle.
 */
function field_ui_inactive_message($entity_type, $bundle) {
	$inactive_instances = field_ui_inactive_instances($entity_type, $bundle);
	if (!empty($inactive_instances)) {
		$field_types = field_info_field_types();
		$widget_types = field_info_widget_types();

		foreach ($inactive_instances as $field_name => $instance) {
			$list[] = t('%field (@field_name) field requires the %widget_type widget provided by %widget_module module', array(
					'%field' => $instance['label'],
					'@field_name' => $instance['field_name'],
					'%widget_type' => isset($widget_types[$instance['widget']['type']]) ? $widget_types[$instance['widget']['type']]['label'] : $instance['widget']['type'],
					'%widget_module' => $instance['widget']['module'],
			));
		}
		drupal_set_message(t('Inactive fields are not shown unless their providing modules are enabled. The following fields are not enabled: !list', array('!list' => theme('item_list', array('items' => $list)))), 'error');
	}
}

/**
 * Determines the rendering order of an array representing a tree.
 *
 * Callback for array_reduce() within field_ui_table_pre_render().
 */
function _field_ui_reduce_order($array, $a) {
	$array = !isset($array) ? array() : $array;
	if ($a['name']) {
		$array[] = $a['name'];
	}
	if (!empty($a['children'])) {
		uasort($a['children'], 'drupal_sort_weight');
		$array = array_merge($array, array_reduce($a['children'], '_field_ui_reduce_order'));
	}
	return $array;
}

/**
 * Returns the region to which a row in the 'Manage fields' screen belongs.
 *
 * This function is used as a #region_callback in
 * field_ui_field_overview_form(). It is called during
 * field_ui_table_pre_render().
 */
function field_ui_field_overview_row_region($row) {
	switch ($row['#row_type']) {
		case 'field':
		case 'extra_field':
			return 'main';
		case 'add_new_field':
			// If no input in 'label', assume the row has not been dragged out of the
			// 'add new' section.
			return (!empty($row['label']['#value']) ? 'main' : 'add_new');
	}
}

/**
 * Returns the region to which a row in the 'Manage display' screen belongs.
 *
 * This function is used as a #region_callback in
 * field_ui_field_overview_form(), and is called during
 * field_ui_table_pre_render().
 */
function field_ui_display_overview_row_region($row) {
	switch ($row['#row_type']) {
		case 'field':
		case 'extra_field':
			return ($row['format']['type']['#value'] == 'hidden' ? 'hidden' : 'visible');
	}
}

/**
 * Pre-render callback for field_ui_table elements.
 */
function field_ui_table_pre_render($elements) {
	$js_settings = array();

	// For each region, build the tree structure from the weight and parenting
	// data contained in the flat form structure, to determine row order and
	// indentation.
	$regions = $elements['#regions'];
	$tree = array('' => array('name' => '', 'children' => array()));
	$trees = array_fill_keys(array_keys($regions), $tree);

	$parents = array();
	$list = drupal_map_assoc(element_children($elements));

	// Iterate on rows until we can build a known tree path for all of them.
	while ($list) {
		foreach ($list as $name) {
			$row = &$elements[$name];
			$parent = $row['parent_wrapper']['parent']['#value'];
			// Proceed if parent is known.
			if (empty($parent) || isset($parents[$parent])) {
				// Grab parent, and remove the row from the next iteration.
				$parents[$name] = $parent ? array_merge($parents[$parent], array($parent)) : array();
				unset($list[$name]);

				// Determine the region for the row.
				$function = $row['#region_callback'];
				$region_name = $function($row);

				// Add the element in the tree.
				$target = &$trees[$region_name][''];
				foreach ($parents[$name] as $key) {
					$target = &$target['children'][$key];
				}
				$target['children'][$name] = array('name' => $name, 'weight' => $row['weight']['#value']);

				// Add tabledrag indentation to the first row cell.
				if ($depth = count($parents[$name])) {
					$cell = current(element_children($row));
					$row[$cell]['#prefix'] = theme('indentation', array('size' => $depth)) . (isset($row[$cell]['#prefix']) ? $row[$cell]['#prefix'] : '');
				}

				// Add row id and associate JS settings.
				$id = drupal_html_class($name);
				$row['#attributes']['id'] = $id;
				if (isset($row['#js_settings'])) {
					$row['#js_settings'] += array(
							'rowHandler' => $row['#row_type'],
							'name' => $name,
							'region' => $region_name,
					);
					$js_settings[$id] = $row['#js_settings'];
				}
			}
		}
	}
	// Determine rendering order from the tree structure.
	foreach ($regions as $region_name => $region) {
		$elements['#regions'][$region_name]['rows_order'] = array_reduce($trees[$region_name], '_field_ui_reduce_order');
	}

	$elements['#attached']['js'][] = array(
			'type' => 'setting',
			'data' => array('fieldUIRowsData' => $js_settings),
	);

	return $elements;
}

/**
 * Returns HTML for Field UI overview tables.
 *
 * @param $variables
 *   An associative array containing:
 *   - elements: An associative array containing a Form API structure to be
 *     rendered as a table.
 *
 * @ingroup themeable
 */
function theme_field_ui_table($variables) {
	$elements = $variables['elements'];
	$table = array();
	$js_settings = array();

	// Add table headers and attributes.
	foreach (array('header', 'attributes') as $key) {
		if (isset($elements["#$key"])) {
			$table[$key] = $elements["#$key"];
		}
	}

	// Determine the colspan to use for region rows, by checking the number of
	// columns in the headers.
	$columns_count = 0;
	foreach ($table['header'] as $header) {
		$columns_count += (is_array($header) && isset($header['colspan']) ? $header['colspan'] : 1);
	}

	// Render rows, region by region.
	foreach ($elements['#regions'] as $region_name => $region) {
		$region_name_class = drupal_html_class($region_name);

		// Add region rows.
		if (isset($region['title'])) {
			$table['rows'][] = array(
					'class' => array('region-title', 'region-' . $region_name_class . '-title'),
					'no_striping' => TRUE,
					'data' => array(
							array('data' => $region['title'], 'colspan' => $columns_count),
					),
			);
		}
		if (isset($region['message'])) {
			$class = (empty($region['rows_order']) ? 'region-empty' : 'region-populated');
			$table['rows'][] = array(
					'class' => array('region-message', 'region-' . $region_name_class . '-message', $class),
					'no_striping' => TRUE,
					'data' => array(
							array('data' => $region['message'], 'colspan' => $columns_count),
					),
			);
		}

		// Add form rows, in the order determined at pre-render time.
		foreach ($region['rows_order'] as $name) {
			$element = $elements[$name];

			$row = array('data' => array());
			if (isset($element['#attributes'])) {
				$row += $element['#attributes'];
			}

			// Render children as table cells.
			foreach (element_children($element) as $cell_key) {
				$child = &$element[$cell_key];
				// Do not render a cell for children of #type 'value'.
				if (!(isset($child['#type']) && $child['#type'] == 'value')) {
					$cell = array('data' => drupal_render($child));
					if (isset($child['#cell_attributes'])) {
						$cell += $child['#cell_attributes'];
					}
					$row['data'][] = $cell;
				}
			}
			$table['rows'][] = $row;
		}
	}

	return theme('table', $table);
}

/**
 * Form constructor for the 'Manage fields' form of a bundle.
 *
 * Allows fields and pseudo-fields to be re-ordered.
 *
 * @see field_ui_overview_form_validate().
 * @see field_ui_overview_form_submit().
 * @ingroup forms
 */
function field_ui_field_overview_form($form, &$form_state, $entity_type, $bundle) {
	$bundle = field_extract_bundle($entity_type, $bundle);

	field_ui_inactive_message($entity_type, $bundle);
	$admin_path = _field_ui_bundle_admin_path($entity_type, $bundle);

	// When displaying the form, make sure the list of fields is up-to-date.
	if (empty($form_state['post'])) {
		field_info_cache_clear();
	}

	// Gather bundle information.
	$instances = field_info_instances($entity_type, $bundle);
	$field_types = field_info_field_types();
	$widget_types = field_info_widget_types();

	$extra_fields = field_info_extra_fields($entity_type, $bundle, 'form');

	$form += array(
			'#entity_type' => $entity_type,
			'#bundle' => $bundle,
			'#fields' => array_keys($instances),
			'#extra' => array_keys($extra_fields),
	);

	$table = array(
			'#type' => 'field_ui_table',
			'#tree' => TRUE,
			'#header' => array(
					t('Label'),
					t('Weight'),
					t('Parent'),
					t('Name'),
					t('Field'),
					t('Widget'),
					array('data' => t('Operations'), 'colspan' => 2),
			),
			'#parent_options' => array(),
			'#regions' => array(
					'main' => array('message' => t('No fields are present yet.')),
					'add_new' => array('title' => '&nbsp;'),
			),
			'#attributes' => array(
					'class' => array('field-ui-overview'),
					'id' => 'field-overview',
			),
	);

	// Fields.
	foreach ($instances as $name => $instance) {
		$field = field_info_field($instance['field_name']);
		$admin_field_path = $admin_path . '/fields/' . $instance['field_name'];
		$table[$name] = array(
				'#attributes' => array('class' => array('draggable', 'tabledrag-leaf')),
				'#row_type' => 'field',
				'#region_callback' => 'field_ui_field_overview_row_region',
				'label' => array(
						'#markup' => check_plain($instance['label']),
				),
				'weight' => array(
						'#type' => 'textfield',
						'#title' => t('Weight for @title', array('@title' => $instance['label'])),
						'#title_display' => 'invisible',
						'#default_value' => $instance['widget']['weight'],
						'#size' => 3,
						'#attributes' => array('class' => array('field-weight')),
				),
				'parent_wrapper' => array(
						'parent' => array(
								'#type' => 'select',
								'#title' => t('Parent for @title', array('@title' => $instance['label'])),
								'#title_display' => 'invisible',
								'#options' => $table['#parent_options'],
								'#empty_value' => '',
								'#attributes' => array('class' => array('field-parent')),
								'#parents' => array('fields', $name, 'parent'),
						),
						'hidden_name' => array(
								'#type' => 'hidden',
								'#default_value' => $name,
								'#attributes' => array('class' => array('field-name')),
						),
				),
				'field_name' => array(
						'#markup' => $instance['field_name'],
				),
				'type' => array(
						'#type' => 'link',
						'#title' => t($field_types[$field['type']]['label']),
						'#href' => $admin_field_path . '/field-settings',
						'#options' => array('attributes' => array('title' => t('Edit field settings.'))),
				),
				'widget_type' => array(
						'#type' => 'link',
						'#title' => t($widget_types[$instance['widget']['type']]['label']),
						'#href' => $admin_field_path . '/widget-type',
						'#options' => array('attributes' => array('title' => t('Change widget type.'))),
				),
				'edit' => array(
						'#type' => 'link',
						'#title' => t('edit'),
						'#href' => $admin_field_path,
						'#options' => array('attributes' => array('title' => t('Edit instance settings.'))),
				),
				'delete' => array(
						'#type' => 'link',
						'#title' => t('delete'),
						'#href' => $admin_field_path . '/delete',
						'#options' => array('attributes' => array('title' => t('Delete instance.'))),
				),
		);

		if (!empty($instance['locked'])) {
			$table[$name]['edit'] = array('#value' => t('Locked'));
			$table[$name]['delete'] = array();
			$table[$name]['#attributes']['class'][] = 'menu-disabled';
		}
	}

	// Non-field elements.
	foreach ($extra_fields as $name => $extra_field) {
		$table[$name] = array(
				'#attributes' => array('class' => array('draggable', 'tabledrag-leaf')),
				'#row_type' => 'extra_field',
				'#region_callback' => 'field_ui_field_overview_row_region',
				'label' => array(
						'#markup' => check_plain($extra_field['label']),
				),
				'weight' => array(
						'#type' => 'textfield',
						'#default_value' => $extra_field['weight'],
						'#size' => 3,
						'#attributes' => array('class' => array('field-weight')),
						'#title_display' => 'invisible',
						'#title' => t('Weight for @title', array('@title' => $extra_field['label'])),
				),
				'parent_wrapper' => array(
						'parent' => array(
								'#type' => 'select',
								'#title' => t('Parent for @title', array('@title' => $extra_field['label'])),
								'#title_display' => 'invisible',
								'#options' => $table['#parent_options'],
								'#empty_value' => '',
								'#attributes' => array('class' => array('field-parent')),
								'#parents' => array('fields', $name, 'parent'),
						),
						'hidden_name' => array(
								'#type' => 'hidden',
								'#default_value' => $name,
								'#attributes' => array('class' => array('field-name')),
						),
				),
				'field_name' => array(
						'#markup' => $name,
				),
				'type' => array(
						'#markup' => isset($extra_field['description']) ? $extra_field['description'] : '',
						'#cell_attributes' => array('colspan' => 2),
				),
				'edit' => array(
						'#markup' => isset($extra_field['edit']) ? $extra_field['edit'] : '',
				),
				'delete' => array(
						'#markup' => isset($extra_field['delete']) ? $extra_field['delete'] : '',
				),
		);
	}

	// Additional row: add new field.
	$max_weight = field_info_max_weight($entity_type, $bundle, 'form');
	$field_type_options = field_ui_field_type_options();
	$widget_type_options = field_ui_widget_type_options(NULL, TRUE);
	if ($field_type_options && $widget_type_options) {
		$name = '_add_new_field';
		$table[$name] = array(
				'#attributes' => array('class' => array('draggable', 'tabledrag-leaf', 'add-new')),
				'#row_type' => 'add_new_field',
				'#region_callback' => 'field_ui_field_overview_row_region',
				'label' => array(
						'#type' => 'textfield',
						'#title' => t('New field label'),
						'#title_display' => 'invisible',
						'#size' => 15,
						'#description' => t('Label'),
						'#prefix' => '<div class="label-input"><div class="add-new-placeholder">' . t('Add new field') .'</div>',
						'#suffix' => '</div>',
				),
				'weight' => array(
						'#type' => 'textfield',
						'#default_value' => $max_weight + 1,
						'#size' => 3,
						'#title_display' => 'invisible',
						'#title' => t('Weight for new field'),
						'#attributes' => array('class' => array('field-weight')),
						'#prefix' => '<div class="add-new-placeholder">&nbsp;</div>',
				),
				'parent_wrapper' => array(
						'parent' => array(
								'#type' => 'select',
								'#title' => t('Parent for new field'),
								'#title_display' => 'invisible',
								'#options' => $table['#parent_options'],
								'#empty_value' => '',
								'#attributes' => array('class' => array('field-parent')),
								'#prefix' => '<div class="add-new-placeholder">&nbsp;</div>',
								'#parents' => array('fields', $name, 'parent'),
						),
						'hidden_name' => array(
								'#type' => 'hidden',
								'#default_value' => $name,
								'#attributes' => array('class' => array('field-name')),
						),
				),
				'field_name' => array(
						'#type' => 'textfield',
						'#title' => t('New field name'),
						'#title_display' => 'invisible',
						// This field should stay LTR even for RTL languages.
						'#field_prefix' => '<span dir="ltr">field_',
						'#field_suffix' => '</span>&lrm;',
						'#attributes' => array('dir'=>'ltr'),
						'#size' => 10,
						'#description' => t('Field name (a-z, 0-9, _)'),
						'#prefix' => '<div class="add-new-placeholder">&nbsp;</div>',
				),
				'type' => array(
						'#type' => 'select',
						'#title' => t('Type of new field'),
						'#title_display' => 'invisible',
						'#options' => $field_type_options,
						'#empty_option' => t('- Select a field type -'),
						'#description' => t('Type of data to store.'),
						'#attributes' => array('class' => array('field-type-select')),
						'#prefix' => '<div class="add-new-placeholder">&nbsp;</div>',
				),
				'widget_type' => array(
						'#type' => 'select',
						'#title' => t('Widget for new field'),
						'#title_display' => 'invisible',
						'#options' => $widget_type_options,
						'#empty_option' => t('- Select a widget -'),
						'#description' => t('Form element to edit the data.'),
						'#attributes' => array('class' => array('widget-type-select')),
						'#cell_attributes' => array('colspan' => 3),
						'#prefix' => '<div class="add-new-placeholder">&nbsp;</div>',
				),
				// Place the 'translatable' property as an explicit value so that contrib
				// modules can form_alter() the value for newly created fields.
				'translatable' => array(
						'#type' => 'value',
						'#value' => FALSE,
				),
		);
	}

	// Additional row: add existing field.
	$existing_field_options = field_ui_existing_field_options($entity_type, $bundle);
	if ($existing_field_options && $widget_type_options) {
		$name = '_add_existing_field';
		$table[$name] = array(
				'#attributes' => array('class' => array('draggable', 'tabledrag-leaf', 'add-new')),
				'#row_type' => 'add_new_field',
				'#region_callback' => 'field_ui_field_overview_row_region',
				'label' => array(
						'#type' => 'textfield',
						'#title' => t('Existing field label'),
						'#title_display' => 'invisible',
						'#size' => 15,
						'#description' => t('Label'),
						'#attributes' => array('class' => array('label-textfield')),
						'#prefix' => '<div class="label-input"><div class="add-new-placeholder">' . t('Add existing field') .'</div>',
						'#suffix' => '</div>',
				),
				'weight' => array(
						'#type' => 'textfield',
						'#default_value' => $max_weight + 2,
						'#size' => 3,
						'#title_display' => 'invisible',
						'#title' => t('Weight for added field'),
						'#attributes' => array('class' => array('field-weight')),
						'#prefix' => '<div class="add-new-placeholder">&nbsp;</div>',
				),
				'parent_wrapper' => array(
						'parent' => array(
								'#type' => 'select',
								'#title' => t('Parent for existing field'),
								'#title_display' => 'invisible',
								'#options' => $table['#parent_options'],
								'#empty_value' => '',
								'#attributes' => array('class' => array('field-parent')),
								'#prefix' => '<div class="add-new-placeholder">&nbsp;</div>',
								'#parents' => array('fields', $name, 'parent'),
						),
						'hidden_name' => array(
								'#type' => 'hidden',
								'#default_value' => $name,
								'#attributes' => array('class' => array('field-name')),
						),
				),
				'field_name' => array(
						'#type' => 'select',
						'#title' => t('Existing field to share'),
						'#title_display' => 'invisible',
						'#options' => $existing_field_options,
						'#empty_option' => t('- Select an existing field -'),
						'#description' => t('Field to share'),
						'#attributes' => array('class' => array('field-select')),
						'#cell_attributes' => array('colspan' => 2),
						'#prefix' => '<div class="add-new-placeholder">&nbsp;</div>',
				),
				'widget_type' => array(
						'#type' => 'select',
						'#title' => t('Widget for existing field'),
						'#title_display' => 'invisible',
						'#options' => $widget_type_options,
						'#empty_option' => t('- Select a widget -'),
						'#description' => t('Form element to edit the data.'),
						'#attributes' => array('class' => array('widget-type-select')),
						'#cell_attributes' => array('colspan' => 3),
						'#prefix' => '<div class="add-new-placeholder">&nbsp;</div>',
				),
		);
	}
	$form['fields'] = $table;

	$form['actions'] = array('#type' => 'actions');
	$form['actions']['submit'] = array('#type' => 'submit', '#value' => t('Save'));

	$form['#attached']['css'][] = drupal_get_path('module', 'field_ui') . '/field_ui.css';
	$form['#attached']['js'][] = drupal_get_path('module', 'field_ui') . '/field_ui.js';

	// Add settings for the update selects behavior.
	$js_fields = array();
	foreach ($existing_field_options as $field_name => $fields) {
		$field = field_info_field($field_name);
		$instance = field_info_instance($form['#entity_type'], $field_name, $form['#bundle']);
		$js_fields[$field_name] = array('label' => $instance['label'], 'type' => $field['type'], 'widget' => $instance['widget']['type']);
	}

	$form['#attached']['js'][] = array(
			'type' => 'setting',
			'data' => array('fields' => $js_fields, 'fieldWidgetTypes' => field_ui_widget_type_options()),
	);

	// Add tabledrag behavior.
	$form['#attached']['drupal_add_tabledrag'][] = array('field-overview', 'order', 'sibling', 'field-weight');
	$form['#attached']['drupal_add_tabledrag'][] = array('field-overview', 'match', 'parent', 'field-parent', 'field-parent', 'field-name');

	return $form;
}

/**
 * Form validation handler for field_ui_field_overview_form().
 *
 * @see field_ui_field_overview_form_submit()
 */
function field_ui_field_overview_form_validate($form, &$form_state) {
	_field_ui_field_overview_form_validate_add_new($form, $form_state);
	_field_ui_field_overview_form_validate_add_existing($form, $form_state);
}

/**
 * Validates the 'add new field' row of field_ui_field_overview_form().
 *
 * @see field_ui_field_overview_form_validate()
 */
function _field_ui_field_overview_form_validate_add_new($form, &$form_state) {
	$field = $form_state['values']['fields']['_add_new_field'];

	// Validate if any information was provided in the 'add new field' row.
	if (array_filter(array($field['label'], $field['field_name'], $field['type'], $field['widget_type']))) {
		// Missing label.
		if (!$field['label']) {
			form_set_error('fields][_add_new_field][label', t('Add new field: you need to provide a label.'));
		}

		// Missing field name.
		if (!$field['field_name']) {
			form_set_error('fields][_add_new_field][field_name', t('Add new field: you need to provide a field name.'));
		}
		// Field name validation.
		else {
			$field_name = $field['field_name'];

			// Add the 'field_' prefix.
			if (substr($field_name, 0, 6) != 'field_') {
				$field_name = 'field_' . $field_name;
				form_set_value($form['fields']['_add_new_field']['field_name'], $field_name, $form_state);
			}

			// Invalid field name.
			if (!preg_match('!^field_[a-z0-9_]+$!', $field_name)) {
				form_set_error('fields][_add_new_field][field_name', t('Add new field: the field name %field_name is invalid. The name must include only lowercase unaccentuated letters, numbers, and underscores.', array('%field_name' => $field_name)));
			}
			if (strlen($field_name) > 32) {
				form_set_error('fields][_add_new_field][field_name', t("Add new field: the field name %field_name is too long. The name is limited to 32 characters, including the 'field_' prefix.", array('%field_name' => $field_name)));
			}

			// Field name already exists. We need to check inactive fields as well, so
			// we can't use field_info_fields().
			$fields = field_read_fields(array('field_name' => $field_name), array('include_inactive' => TRUE));
			if ($fields) {
				form_set_error('fields][_add_new_field][field_name', t('Add new field: the field name %field_name already exists.', array('%field_name' => $field_name)));
			}
		}

		// Missing field type.
		if (!$field['type']) {
			form_set_error('fields][_add_new_field][type', t('Add new field: you need to select a field type.'));
		}

		// Missing widget type.
		if (!$field['widget_type']) {
			form_set_error('fields][_add_new_field][widget_type', t('Add new field: you need to select a widget.'));
		}
		// Wrong widget type.
		elseif ($field['type']) {
			$widget_types = field_ui_widget_type_options($field['type']);
			if (!isset($widget_types[$field['widget_type']])) {
				form_set_error('fields][_add_new_field][widget_type', t('Add new field: invalid widget.'));
			}
		}
	}
}

/**
 * Validates the 'add existing field' row of field_ui_field_overview_form().
 *
 * @see field_ui_field_overview_form_validate()
 */
function _field_ui_field_overview_form_validate_add_existing($form, &$form_state) {
	// The form element might be absent if no existing fields can be added to
	// this bundle.
	if (isset($form_state['values']['fields']['_add_existing_field'])) {
		$field = $form_state['values']['fields']['_add_existing_field'];

		// Validate if any information was provided in the 'add existing field' row.
		if (array_filter(array($field['label'], $field['field_name'], $field['widget_type']))) {
			// Missing label.
			if (!$field['label']) {
				form_set_error('fields][_add_existing_field][label', t('Add existing field: you need to provide a label.'));
			}

			// Missing existing field name.
			if (!$field['field_name']) {
				form_set_error('fields][_add_existing_field][field_name', t('Add existing field: you need to select a field.'));
			}

			// Missing widget type.
			if (!$field['widget_type']) {
				form_set_error('fields][_add_existing_field][widget_type', t('Add existing field: you need to select a widget.'));
			}
			// Wrong widget type.
			elseif ($field['field_name'] && ($existing_field = field_info_field($field['field_name']))) {
				$widget_types = field_ui_widget_type_options($existing_field['type']);
				if (!isset($widget_types[$field['widget_type']])) {
					form_set_error('fields][_add_existing_field][widget_type', t('Add existing field: invalid widget.'));
				}
			}
		}
	}
}

/**
 * Form submission handler for field_ui_field_overview_form().
 *
 * @see field_ui_field_overview_form_validate()
 */
function field_ui_field_overview_form_submit($form, &$form_state) {
	$form_values = $form_state['values']['fields'];
	$entity_type = $form['#entity_type'];
	$bundle = $form['#bundle'];
	$admin_path = _field_ui_bundle_admin_path($entity_type, $bundle);

	$bundle_settings = field_bundle_settings($entity_type, $bundle);

	// Update field weights.
	foreach ($form_values as $key => $values) {
		if (in_array($key, $form['#fields'])) {
			$instance = field_read_instance($entity_type, $key, $bundle);
			$instance['widget']['weight'] = $values['weight'];
			field_update_instance($instance);
		}
		elseif (in_array($key, $form['#extra'])) {
			$bundle_settings['extra_fields']['form'][$key]['weight'] = $values['weight'];
		}
	}

	field_bundle_settings($entity_type, $bundle, $bundle_settings);

	$destinations = array();

	// Create new field.
	$field = array();
	if (!empty($form_values['_add_new_field']['field_name'])) {
		$values = $form_values['_add_new_field'];

		$field = array(
				'field_name' => $values['field_name'],
				'type' => $values['type'],
				'translatable' => $values['translatable'],
		);
		$instance = array(
				'field_name' => $field['field_name'],
				'entity_type' => $entity_type,
				'bundle' => $bundle,
				'label' => $values['label'],
				'widget' => array(
						'type' => $values['widget_type'],
						'weight' => $values['weight'],
				),
		);

		// Create the field and instance.
		try {
			field_create_field($field);
			field_create_instance($instance);

			$destinations[] = $admin_path . '/fields/' . $field['field_name'] . '/field-settings';
			$destinations[] = $admin_path . '/fields/' . $field['field_name'];

			// Store new field information for any additional submit handlers.
			$form_state['fields_added']['_add_new_field'] = $field['field_name'];
		}
		catch (Exception $e) {
			drupal_set_message(t('There was a problem creating field %label: !message', array('%label' => $instance['label'], '!message' => $e->getMessage())), 'error');
		}
	}

	// Add existing field.
	if (!empty($form_values['_add_existing_field']['field_name'])) {
		$values = $form_values['_add_existing_field'];
		$field = field_info_field($values['field_name']);
		if (!empty($field['locked'])) {
			drupal_set_message(t('The field %label cannot be added because it is locked.', array('%label' => $values['label'])), 'error');
		}
		else {
			$instance = array(
					'field_name' => $field['field_name'],
					'entity_type' => $entity_type,
					'bundle' => $bundle,
					'label' => $values['label'],
					'widget' => array(
							'type' => $values['widget_type'],
							'weight' => $values['weight'],
					),
			);

			try {
				field_create_instance($instance);
				$destinations[] = $admin_path . '/fields/' . $instance['field_name'] . '/edit';
				// Store new field information for any additional submit handlers.
				$form_state['fields_added']['_add_existing_field'] = $instance['field_name'];
			}
			catch (Exception $e) {
				drupal_set_message(t('There was a problem creating field instance %label: @message.', array('%label' => $instance['label'], '@message' => $e->getMessage())), 'error');
			}
		}
	}

	if ($destinations) {
		$destination = drupal_get_destination();
		$destinations[] = $destination['destination'];
		unset($_GET['destination']);
		$form_state['redirect'] = field_ui_get_destinations($destinations);
	}
	else {
		drupal_set_message(t('Your settings have been saved.'));
	}
}

/**
 * Form constructor for the field display settings for a given view mode.
 *
 * @see field_ui_display_overview_multistep_submit()
 * @see field_ui_display_overview_form_submit()
 * @ingroup forms
 */
function field_ui_display_overview_form($form, &$form_state, $entity_type, $bundle, $view_mode) {
	$bundle = field_extract_bundle($entity_type, $bundle);

	field_ui_inactive_message($entity_type, $bundle);
	$admin_path = _field_ui_bundle_admin_path($entity_type, $bundle);

	// Gather type information.
	$instances = field_info_instances($entity_type, $bundle);
	$field_types = field_info_field_types();
	$extra_fields = field_info_extra_fields($entity_type, $bundle, 'display');

	$form_state += array(
			'formatter_settings_edit' => NULL,
	);

	$form += array(
			'#entity_type' => $entity_type,
			'#bundle' => $bundle,
			'#view_mode' => $view_mode,
			'#fields' => array_keys($instances),
			'#extra' => array_keys($extra_fields),
	);

	if (empty($instances) && empty($extra_fields)) {
		drupal_set_message(t('There are no fields yet added. You can add new fields on the <a href="@link">Manage fields</a> page.', array('@link' => url($admin_path . '/fields'))), 'warning');
		return $form;
	}

	$table = array(
			'#type' => 'field_ui_table',
			'#tree' => TRUE,
			'#header' => array(
					t('Field'),
					t('Weight'),
					t('Parent'),
					t('Label'),
					array('data' => t('Format'), 'colspan' => 3),
			),
			'#regions' => array(
					'visible' => array('message' => t('No field is displayed.')),
					'hidden' => array('title' => t('Hidden'), 'message' => t('No field is hidden.')),
			),
			'#parent_options' => array(),
			'#attributes' => array(
					'class' => array('field-ui-overview'),
					'id' => 'field-display-overview',
			),
			// Add Ajax wrapper.
			'#prefix' => '<div id="field-display-overview-wrapper">',
			'#suffix' => '</div>',
	);

	$field_label_options = array(
			'above' => t('Above'),
			'inline' => t('Inline'),
			'hidden' => t('<Hidden>'),
	);
	$extra_visibility_options = array(
			'visible' => t('Visible'),
			'hidden' => t('Hidden'),
	);

	// Field rows.
	foreach ($instances as $name => $instance) {
		$field = field_info_field($instance['field_name']);
		$display = $instance['display'][$view_mode];
		$table[$name] = array(
				'#attributes' => array('class' => array('draggable', 'tabledrag-leaf')),
				'#row_type' => 'field',
				'#region_callback' => 'field_ui_display_overview_row_region',
				'#js_settings' => array(
						'rowHandler' => 'field',
						'defaultFormatter' => $field_types[$field['type']]['default_formatter'],
				),
				'human_name' => array(
						'#markup' => check_plain($instance['label']),
				),
				'weight' => array(
						'#type' => 'textfield',
						'#title' => t('Weight for @title', array('@title' => $instance['label'])),
						'#title_display' => 'invisible',
						'#default_value' => $display['weight'],
						'#size' => 3,
						'#attributes' => array('class' => array('field-weight')),
				),
				'parent_wrapper' => array(
						'parent' => array(
								'#type' => 'select',
								'#title' => t('Label display for @title', array('@title' => $instance['label'])),
								'#title_display' => 'invisible',
								'#options' => $table['#parent_options'],
								'#empty_value' => '',
								'#attributes' => array('class' => array('field-parent')),
								'#parents' => array('fields', $name, 'parent'),
						),
						'hidden_name' => array(
								'#type' => 'hidden',
								'#default_value' => $name,
								'#attributes' => array('class' => array('field-name')),
						),
				),
				'label' => array(
						'#type' => 'select',
						'#title' => t('Label display for @title', array('@title' => $instance['label'])),
						'#title_display' => 'invisible',
						'#options' => $field_label_options,
						'#default_value' => $display['label'],
				),
		);

		$formatter_options = field_ui_formatter_options($field['type']);
		$formatter_options['hidden'] = t('<Hidden>');
		$table[$name]['format'] = array(
				'type' => array(
						'#type' => 'select',
						'#title' => t('Formatter for @title', array('@title' => $instance['label'])),
						'#title_display' => 'invisible',
						'#options' => $formatter_options,
						'#default_value' => $display['type'],
						'#parents' => array('fields', $name, 'type'),
						'#attributes' => array('class' => array('field-formatter-type')),
				),
				'settings_edit_form' => array(),
		);

		// Formatter settings.

		// Check the currently selected formatter, and merge persisted values for
		// formatter settings.
		if (isset($form_state['values']['fields'][$name]['type'])) {
			$formatter_type = $form_state['values']['fields'][$name]['type'];
		}
		else {
			$formatter_type = $display['type'];
		}
		if (isset($form_state['formatter_settings'][$name])) {
			$settings = $form_state['formatter_settings'][$name];
		}
		else {
			$settings = $display['settings'];
		}
		$settings += field_info_formatter_settings($formatter_type);

		$instance['display'][$view_mode]['type'] = $formatter_type;
		$formatter = field_info_formatter_types($formatter_type);
		$instance['display'][$view_mode]['module'] = $formatter['module'];
		$instance['display'][$view_mode]['settings'] = $settings;

		// Base button element for the various formatter settings actions.
		$base_button = array(
				'#submit' => array('field_ui_display_overview_multistep_submit'),
				'#ajax' => array(
						'callback' => 'field_ui_display_overview_multistep_js',
						'wrapper' => 'field-display-overview-wrapper',
						'effect' => 'fade',
				),
				'#field_name' => $name,
		);

		if ($form_state['formatter_settings_edit'] == $name) {
			// We are currently editing this field's formatter settings. Display the
			// settings form and submit buttons.
			$table[$name]['format']['settings_edit_form'] = array();

			$settings_form = array();
			$function = $formatter['module'] . '_field_formatter_settings_form';
			if (function_exists($function)) {
				$settings_form = $function($field, $instance, $view_mode, $form, $form_state);
			}

			if ($settings_form) {
				$table[$name]['format']['#cell_attributes'] = array('colspan' => 3);
				$table[$name]['format']['settings_edit_form'] = array(
						'#type' => 'container',
						'#attributes' => array('class' => array('field-formatter-settings-edit-form')),
						'#parents' => array('fields', $name, 'settings_edit_form'),
						'label' => array(
								'#markup' => t('Format settings:') . ' <span class="formatter-name">' . $formatter['label'] . '</span>',
						),
						'settings' => $settings_form,
						'actions' => array(
								'#type' => 'actions',
								'save_settings' => $base_button + array(
										'#type' => 'submit',
										'#name' => $name . '_formatter_settings_update',
										'#value' => t('Update'),
										'#op' => 'update',
								),
								'cancel_settings' => $base_button + array(
										'#type' => 'submit',
										'#name' => $name . '_formatter_settings_cancel',
										'#value' => t('Cancel'),
										'#op' => 'cancel',
										// Do not check errors for the 'Cancel' button, but make sure we
										// get the value of the 'formatter type' select.
										'#limit_validation_errors' => array(array('fields', $name, 'type')),
								),
						),
				);
				$table[$name]['#attributes']['class'][] = 'field-formatter-settings-editing';
			}
		}
		else {
			// Display a summary of the current formatter settings.
			$summary = module_invoke($formatter['module'], 'field_formatter_settings_summary', $field, $instance, $view_mode);
			$table[$name]['settings_summary'] = array();
			$table[$name]['settings_edit'] = array();
			if ($summary) {
				$table[$name]['settings_summary'] = array(
						'#markup' => '<div class="field-formatter-summary">' . $summary . '</div>',
						'#cell_attributes' => array('class' => array('field-formatter-summary-cell')),
				);
				$table[$name]['settings_edit'] = $base_button + array(
						'#type' => 'image_button',
						'#name' => $name . '_formatter_settings_edit',
						'#src' => 'misc/configure.png',
						'#attributes' => array('class' => array('field-formatter-settings-edit'), 'alt' => t('Edit')),
						'#op' => 'edit',
						// Do not check errors for the 'Edit' button, but make sure we get
						// the value of the 'formatter type' select.
						'#limit_validation_errors' => array(array('fields', $name, 'type')),
						'#prefix' => '<div class="field-formatter-settings-edit-wrapper">',
						'#suffix' => '</div>',
				);
			}
		}
	}

	// Non-field elements.
	foreach ($extra_fields as $name => $extra_field) {
		$display = $extra_field['display'][$view_mode];
		$table[$name] = array(
				'#attributes' => array('class' => array('draggable', 'tabledrag-leaf')),
				'#row_type' => 'extra_field',
				'#region_callback' => 'field_ui_display_overview_row_region',
				'#js_settings' => array('rowHandler' => 'field'),
				'human_name' => array(
						'#markup' => check_plain($extra_field['label']),
				),
				'weight' => array(
						'#type' => 'textfield',
						'#title' => t('Weight for @title', array('@title' => $extra_field['label'])),
						'#title_display' => 'invisible',
						'#default_value' => $display['weight'],
						'#size' => 3,
						'#attributes' => array('class' => array('field-weight')),
				),
				'parent_wrapper' => array(
						'parent' => array(
								'#type' => 'select',
								'#title' => t('Parents for @title', array('@title' => $extra_field['label'])),
								'#title_display' => 'invisible',
								'#options' => $table['#parent_options'],
								'#empty_value' => '',
								'#attributes' => array('class' => array('field-parent')),
								'#parents' => array('fields', $name, 'parent'),
						),
						'hidden_name' => array(
								'#type' => 'hidden',
								'#default_value' => $name,
								'#attributes' => array('class' => array('field-name')),
						),
				),
				'empty_cell' => array(
						'#markup' => '&nbsp;',
				),
				'format' => array(
						'type' => array(
								'#type' => 'select',
								'#title' => t('Visibility for @title', array('@title' => $extra_field['label'])),
								'#title_display' => 'invisible',
								'#options' => $extra_visibility_options,
								'#default_value' => $display['visible'] ? 'visible' : 'hidden',
								'#parents' => array('fields', $name, 'type'),
								'#attributes' => array('class' => array('field-formatter-type')),
						),
				),
				'settings_summary' => array(),
				'settings_edit' => array(),
		);
	}

	$form['fields'] = $table;

	// Custom display settings.
	if ($view_mode == 'default') {
		$form['modes'] = array(
				'#type' => 'fieldset',
				'#title' => t('Custom display settings'),
				'#collapsible' => TRUE,
				'#collapsed' => TRUE,
		);
		// Collect options and default values for the 'Custom display settings'
		// checkboxes.
		$options = array();
		$default = array();
		$entity_info = entity_get_info($entity_type);
		$view_modes = $entity_info['view modes'];
		$view_mode_settings = field_view_mode_settings($entity_type, $bundle);
		foreach ($view_modes as $view_mode_name => $view_mode_info) {
			$options[$view_mode_name] = $view_mode_info['label'];
			if (!empty($view_mode_settings[$view_mode_name]['custom_settings'])) {
				$default[] = $view_mode_name;
			}
		}
		$form['modes']['view_modes_custom'] = array(
				'#type' => 'checkboxes',
				'#title' => t('Use custom display settings for the following view modes'),
				'#options' => $options,
				'#default_value' => $default,
		);
	}

	// In overviews involving nested rows from contributed modules (i.e
	// field_group), the 'format type' selects can trigger a series of changes in
	// child rows. The #ajax behavior is therefore not attached directly to the
	// selects, but triggered by the client-side script through a hidden #ajax
	// 'Refresh' button. A hidden 'refresh_rows' input tracks the name of
	// affected rows.
	$form['refresh_rows'] = array('#type' => 'hidden');
	$form['refresh'] = array(
			'#type' => 'submit',
			'#value' => t('Refresh'),
			'#op' => 'refresh_table',
			'#submit' => array('field_ui_display_overview_multistep_submit'),
			'#ajax' => array(
					'callback' => 'field_ui_display_overview_multistep_js',
					'wrapper' => 'field-display-overview-wrapper',
					'effect' => 'fade',
					// The button stays hidden, so we hide the Ajax spinner too. Ad-hoc
					// spinners will be added manually by the client-side script.
					'progress' => 'none',
			),
	);

	$form['actions'] = array('#type' => 'actions');
	$form['actions']['submit'] = array('#type' => 'submit', '#value' => t('Save'));

	$form['#attached']['js'][] = drupal_get_path('module', 'field_ui') . '/field_ui.js';
	$form['#attached']['css'][] = drupal_get_path('module', 'field_ui') . '/field_ui.css';

	// Add tabledrag behavior.
	$form['#attached']['drupal_add_tabledrag'][] = array('field-display-overview', 'order', 'sibling', 'field-weight');
	$form['#attached']['drupal_add_tabledrag'][] = array('field-display-overview', 'match', 'parent', 'field-parent', 'field-parent', 'field-name');

	return $form;
}


/**
 * Form submission handler for buttons in field_ui_display_overview_form().
 */
function field_ui_display_overview_multistep_submit($form, &$form_state) {
	$trigger = $form_state['triggering_element'];
	$op = $trigger['#op'];

	switch ($op) {
		case 'edit':
			// Store the field whose settings are currently being edited.
			$field_name = $trigger['#field_name'];
			$form_state['formatter_settings_edit'] = $field_name;
			break;

		case 'update':
			// Store the saved settings, and set the field back to 'non edit' mode.
			$field_name = $trigger['#field_name'];
			$values = $form_state['values']['fields'][$field_name]['settings_edit_form']['settings'];
			$form_state['formatter_settings'][$field_name] = $values;
			unset($form_state['formatter_settings_edit']);
			break;

		case 'cancel':
			// Set the field back to 'non edit' mode.
			unset($form_state['formatter_settings_edit']);
			break;

		case 'refresh_table':
			// If the currently edited field is one of the rows to be refreshed, set
			// it back to 'non edit' mode.
			$updated_rows = explode(' ', $form_state['values']['refresh_rows']);
			if (isset($form_state['formatter_settings_edit']) && in_array($form_state['formatter_settings_edit'], $updated_rows)) {
				unset($form_state['formatter_settings_edit']);
			}
			break;
	}

	$form_state['rebuild'] = TRUE;
}

/**
 * Ajax handler for multistep buttons on the 'Manage display' screen.
 */
function field_ui_display_overview_multistep_js($form, &$form_state) {
	$trigger = $form_state['triggering_element'];
	$op = $trigger['#op'];

	// Pick the elements that need to receive the ajax-new-content effect.
	switch ($op) {
		case 'edit':
			$updated_rows = array($trigger['#field_name']);
			$updated_columns = array('format');
			break;

		case 'update':
		case 'cancel':
			$updated_rows = array($trigger['#field_name']);
			$updated_columns = array('format', 'settings_summary', 'settings_edit');
			break;

		case 'refresh_table':
			$updated_rows = array_values(explode(' ', $form_state['values']['refresh_rows']));
			$updated_columns = array('settings_summary', 'settings_edit');
			break;
	}

	foreach ($updated_rows as $name) {
		foreach ($updated_columns as $key) {
			$element = &$form['fields'][$name][$key];
			$element['#prefix'] = '<div class="ajax-new-content">' . (isset($element['#prefix']) ? $element['#prefix'] : '');
			$element['#suffix'] = (isset($element['#suffix']) ? $element['#suffix'] : '') . '</div>';
		}
	}

	// Return the whole table.
	return $form['fields'];
}

/**
 * Form submission handler for field_ui_display_overview_form().
 */
function field_ui_display_overview_form_submit($form, &$form_state) {
	$form_values = $form_state['values'];
	$entity_type = $form['#entity_type'];
	$bundle = $form['#bundle'];
	$view_mode = $form['#view_mode'];

	// Save data for 'regular' fields.
	foreach ($form['#fields'] as $field_name) {
		// Retrieve the stored instance settings to merge with the incoming values.
		$instance = field_read_instance($entity_type, $field_name, $bundle);
		$values = $form_values['fields'][$field_name];
		// Get formatter settings. They lie either directly in submitted form
		// values (if the whole form was submitted while some formatter
		// settings were being edited), or have been persisted in
		// $form_state.
		$settings = array();
		if (isset($values['settings_edit_form']['settings'])) {
			$settings = $values['settings_edit_form']['settings'];
		}
		elseif (isset($form_state['formatter_settings'][$field_name])) {
			$settings = $form_state['formatter_settings'][$field_name];
		}
		elseif (isset($instance['display'][$view_mode]['settings'])) {
			$settings = $instance['display'][$view_mode]['settings'];
		}

		// Only save settings actually used by the selected formatter.
		$default_settings = field_info_formatter_settings($values['type']);
		$settings = array_intersect_key($settings, $default_settings);

		$instance['display'][$view_mode] = array(
				'label' => $values['label'],
				'type' => $values['type'],
				'weight' => $values['weight'],
				'settings' => $settings,
		);
		field_update_instance($instance);
	}

	// Get current bundle settings.
	$bundle_settings = field_bundle_settings($entity_type, $bundle);

	// Save data for 'extra' fields.
	foreach ($form['#extra'] as $name) {
		$bundle_settings['extra_fields']['display'][$name][$view_mode] = array(
				'weight' => $form_values['fields'][$name]['weight'],
				'visible' => $form_values['fields'][$name]['type'] == 'visible',
		);
	}

	// Save view modes data.
	if ($view_mode == 'default') {
		$entity_info = entity_get_info($entity_type);
		foreach ($form_values['view_modes_custom'] as $view_mode_name => $value) {
			// Display a message for each view mode newly configured to use custom
			// settings.
			$view_mode_settings = field_view_mode_settings($entity_type, $bundle);
			if (!empty($value) && empty($view_mode_settings[$view_mode_name]['custom_settings'])) {
				$view_mode_label = $entity_info['view modes'][$view_mode_name]['label'];
				$path = _field_ui_bundle_admin_path($entity_type, $bundle) . "/display/$view_mode_name";
				drupal_set_message(t('The %view_mode mode now uses custom display settings. You might want to <a href="@url">configure them</a>.', array('%view_mode' => $view_mode_label, '@url' => url($path))));
				// Initialize the newly customized view mode with the display settings
				// from the default view mode.
				_field_ui_add_default_view_mode_settings($entity_type, $bundle, $view_mode_name, $bundle_settings);
			}
			$bundle_settings['view_modes'][$view_mode_name]['custom_settings'] = !empty($value);
		}
	}

	// Save updated bundle settings.
	field_bundle_settings($entity_type, $bundle, $bundle_settings);

	drupal_set_message(t('Your settings have been saved.'));
}

/**
 * Populates display settings for a new view mode from the default view mode.
 *
 * When an administrator decides to use custom display settings for a view mode,
 * that view mode needs to be initialized with the display settings for the
 * 'default' view mode, which it was previously using. This helper function
 * adds the new custom display settings to this bundle's instances, and saves
 * them. It also modifies the passed-in $settings array, which the caller can
 * then save using field_bundle_settings().
 *
 * @param $entity_type
 *   The bundle's entity type.
 * @param $bundle
 *   The bundle whose view mode is being customized.
 * @param $view_mode
 *   The view mode that the administrator has set to use custom settings.
 * @param $settings
 *   An associative array of bundle settings, as expected by
 *   field_bundle_settings().
 *
 * @see field_ui_display_overview_form_submit().
 * @see field_bundle_settings()
 */
function _field_ui_add_default_view_mode_settings($entity_type, $bundle, $view_mode, &$settings) {
	// Update display settings for field instances.
	$instances = field_read_instances(array('entity_type' => $entity_type, 'bundle' => $bundle));
	foreach ($instances as $instance) {
		// If this field instance has display settings defined for this view mode,
		// respect those settings.
		if (!isset($instance['display'][$view_mode])) {
			// The instance doesn't specify anything for this view mode, so use the
			// default display settings.
			$instance['display'][$view_mode] = $instance['display']['default'];
			field_update_instance($instance);
		}
	}

	// Update display settings for 'extra fields'.
	foreach (array_keys($settings['extra_fields']['display']) as $name) {
		if (!isset($settings['extra_fields']['display'][$name][$view_mode])) {
			$settings['extra_fields']['display'][$name][$view_mode] = $settings['extra_fields']['display'][$name]['default'];
		}
	}
}

/**
 * Returns an array of field_type options.
 */
function field_ui_field_type_options() {
	$options = &drupal_static(__FUNCTION__);

	if (!isset($options)) {
		$options = array();
		$field_types = field_info_field_types();
		$field_type_options = array();
		foreach ($field_types as $name => $field_type) {
			// Skip field types which have no widget types, or should not be add via
			// uesr interface.
			if (field_ui_widget_type_options($name) && empty($field_type['no_ui'])) {
				$options[$name] = $field_type['label'];
			}
		}
		asort($options);
	}
	return $options;
}

/**
 * Returns an array of widget type options for a field type.
 *
 * If no field type is provided, returns a nested array of all widget types,
 * keyed by field type human name.
 */
function field_ui_widget_type_options($field_type = NULL, $by_label = FALSE) {
	$options = &drupal_static(__FUNCTION__);

	if (!isset($options)) {
		$options = array();
		$field_types = field_info_field_types();
		foreach (field_info_widget_types() as $name => $widget_type) {
			foreach ($widget_type['field types'] as $widget_field_type) {
				// Check that the field type exists.
				if (isset($field_types[$widget_field_type])) {
					$options[$widget_field_type][$name] = $widget_type['label'];
				}
			}
		}
	}

	if (isset($field_type)) {
		return !empty($options[$field_type]) ? $options[$field_type] : array();
	}
	if ($by_label) {
		$field_types = field_info_field_types();
		$options_by_label = array();
		foreach ($options as $field_type => $widgets) {
			$options_by_label[$field_types[$field_type]['label']] = $widgets;
		}
		return $options_by_label;
	}
	return $options;
}

/**
 * Returns an array of formatter options for a field type.
 *
 * If no field type is provided, returns a nested array of all formatters, keyed
 * by field type.
 */
function field_ui_formatter_options($field_type = NULL) {
	$options = &drupal_static(__FUNCTION__);

	if (!isset($options)) {
		$field_types = field_info_field_types();
		$options = array();
		foreach (field_info_formatter_types() as $name => $formatter) {
			foreach ($formatter['field types'] as $formatter_field_type) {
				// Check that the field type exists.
				if (isset($field_types[$formatter_field_type])) {
					$options[$formatter_field_type][$name] = $formatter['label'];
				}
			}
		}
	}

	if ($field_type) {
		return !empty($options[$field_type]) ? $options[$field_type] : array();
	}
	return $options;
}

/**
 * Returns an array of existing fields to be added to a bundle.
 */
function field_ui_existing_field_options($entity_type, $bundle) {
	$options = array();
	$field_types = field_info_field_types();

	foreach (field_info_instances() as $existing_entity_type => $bundles) {
		foreach ($bundles as $existing_bundle => $instances) {
			// No need to look in the current bundle.
			if (!($existing_bundle == $bundle && $existing_entity_type == $entity_type)) {
				foreach ($instances as $instance) {
					$field = field_info_field($instance['field_name']);
					// Don't show
					// - locked fields,
					// - fields already in the current bundle,
					// - fields that cannot be added to the entity type,
					// - fields that that shoud not be added via user interface.

					if (empty($field['locked'])
							&& !field_info_instance($entity_type, $field['field_name'], $bundle)
							&& (empty($field['entity_types']) || in_array($entity_type, $field['entity_types']))
							&& empty($field_types[$field['type']]['no_ui'])) {
						$text = t('@type: @field (@label)', array(
								'@type' => $field_types[$field['type']]['label'],
								'@label' => t($instance['label']), '@field' => $instance['field_name'],
						));
						$options[$instance['field_name']] = (drupal_strlen($text) > 80 ? truncate_utf8($text, 77) . '...' : $text);
					}
				}
			}
		}
	}
	// Sort the list by field name.
	asort($options);
	return $options;
}

/**
 * Form constructor for the field settings edit page.
 *
 * @see field_ui_settings_form_submit()
 * @ingroups forms
 */
function field_ui_field_settings_form($form, &$form_state, $instance) {
	$bundle = $instance['bundle'];
	$entity_type = $instance['entity_type'];
	$field = field_info_field($instance['field_name']);

	drupal_set_title($instance['label']);

	$description = '<p>' . t('These settings apply to the %field field everywhere it is used. These settings impact the way that data is stored in the database and cannot be changed once data has been created.', array('%field' => $instance['label'])) . '</p>';

	// Create a form structure for the field values.
	$form['field'] = array(
			'#type' => 'fieldset',
			'#title' => t('Field settings'),
			'#description' => $description,
			'#tree' => TRUE,
	);

	// See if data already exists for this field.
	// If so, prevent changes to the field settings.
	$has_data = field_has_data($field);
	if ($has_data) {
		$form['field']['#description'] = '<div class="messages error">' . t('There is data for this field in the database. The field settings can no longer be changed.') . '</div>' . $form['field']['#description'];
	}

	// Build the non-configurable field values.
	$form['field']['field_name'] = array('#type' => 'value', '#value' => $field['field_name']);
	$form['field']['type'] = array('#type' => 'value', '#value' => $field['type']);
	$form['field']['module'] = array('#type' => 'value', '#value' => $field['module']);
	$form['field']['active'] = array('#type' => 'value', '#value' => $field['active']);

	// Add settings provided by the field module. The field module is
	// responsible for not returning settings that cannot be changed if
	// the field already has data.
	$form['field']['settings'] = array();
	$additions = module_invoke($field['module'], 'field_settings_form', $field, $instance, $has_data);
	if (is_array($additions)) {
		$form['field']['settings'] = $additions;
	}
	if (empty($form['field']['settings'])) {
		$form['field']['settings'] = array(
				'#markup' => t('%field has no field settings.', array('%field' => $instance['label'])),
		);
	}
	$form['#entity_type'] = $entity_type;
	$form['#bundle'] = $bundle;

	$form['actions'] = array('#type' => 'actions');
	$form['actions']['submit'] = array('#type' => 'submit', '#value' => t('Save field settings'));
	return $form;
}

/**
 * Form submission handler for field_ui_field_settings_form().
 */
function field_ui_field_settings_form_submit($form, &$form_state) {
	$form_values = $form_state['values'];
	$field_values = $form_values['field'];

	// Merge incoming form values into the existing field.
	$field = field_info_field($field_values['field_name']);

	$entity_type = $form['#entity_type'];
	$bundle = $form['#bundle'];
	$instance = field_info_instance($entity_type, $field['field_name'], $bundle);

	// Update the field.
	$field = array_merge($field, $field_values);

	try {
		field_update_field($field);
		drupal_set_message(t('Updated field %label field settings.', array('%label' => $instance['label'])));
		$form_state['redirect'] = field_ui_next_destination($entity_type, $bundle);
	}
	catch (Exception $e) {
		drupal_set_message(t('Attempt to update field %label failed: %message.', array('%label' => $instance['label'], '%message' => $e->getMessage())), 'error');
	}
}

/**
 * Form constructor for the widget selection form.
 *
 * Path: BUNDLE_ADMIN_PATH/fields/%field/widget-type, where BUNDLE_ADMIN_PATH is
 * the path stored in the ['admin']['info'] property in the return value of
 * hook_entity_info().
 *
 * @see field_ui_menu()
 * @see field_ui_widget_type_form_submit()
 * @ingroup forms
 */
function field_ui_widget_type_form($form, &$form_state, $instance) {
	drupal_set_title($instance['label']);

	$bundle = $instance['bundle'];
	$entity_type = $instance['entity_type'];
	$field_name = $instance['field_name'];

	$field = field_info_field($field_name);
	$field_type = field_info_field_types($field['type']);
	$widget_type = field_info_widget_types($instance['widget']['type']);
	$bundles = field_info_bundles();
	$bundle_label = $bundles[$entity_type][$bundle]['label'];

	$form = array(
			'#bundle' => $bundle,
			'#entity_type' => $entity_type,
			'#field_name' => $field_name,
	);

	$form['basic'] = array(
			'#type' => 'fieldset',
			'#title' => t('Change widget'),
	);
	$form['basic']['widget_type'] = array(
			'#type' => 'select',
			'#title' => t('Widget type'),
			'#required' => TRUE,
			'#options' => field_ui_widget_type_options($field['type']),
			'#default_value' => $instance['widget']['type'],
			'#description' => t('The type of form element you would like to present to the user when creating this field in the %type type.', array('%type' => $bundle_label)),
	);

	$form['actions'] = array('#type' => 'actions');
	$form['actions']['submit'] = array('#type' => 'submit', '#value' => t('Continue'));

	$form['#validate'] = array();
	$form['#submit'] = array('field_ui_widget_type_form_submit');

	return $form;
}

/**
 * Form submission handler for field_ui_widget_type_form().
 */
function field_ui_widget_type_form_submit($form, &$form_state) {
	$form_values = $form_state['values'];
	$bundle = $form['#bundle'];
	$entity_type = $form['#entity_type'];
	$field_name = $form['#field_name'];

	// Retrieve the stored instance settings to merge with the incoming values.
	$instance = field_read_instance($entity_type, $field_name, $bundle);

	// Set the right module information.
	$widget_type = field_info_widget_types($form_values['widget_type']);
	$widget_module = $widget_type['module'];

	$instance['widget']['type'] = $form_values['widget_type'];
	$instance['widget']['module'] = $widget_module;

	try {
		field_update_instance($instance);
		drupal_set_message(t('Changed the widget for field %label.', array('%label' => $instance['label'])));
	}
	catch (Exception $e) {
		drupal_set_message(t('There was a problem changing the widget for field %label.', array('%label' => $instance['label'])), 'error');
	}

	$form_state['redirect'] = field_ui_next_destination($entity_type, $bundle);
}

/**
 * Form constructor for removing a field instance from a bundle.
 *
 * @see field_ui_delete_form_submit()
 * @ingroup forms
 */
function field_ui_field_delete_form($form, &$form_state, $instance) {
	$bundle = $instance['bundle'];
	$entity_type = $instance['entity_type'];
	$field = field_info_field($instance['field_name']);

	$admin_path = _field_ui_bundle_admin_path($entity_type, $bundle);

	$form['entity_type'] = array('#type' => 'value', '#value' => $entity_type);
	$form['bundle'] = array('#type' => 'value', '#value' => $bundle);
	$form['field_name'] = array('#type' => 'value', '#value' => $field['field_name']);

	$output = confirm_form($form,
			t('Are you sure you want to delete the field %field?', array('%field' => $instance['label'])),
			$admin_path . '/fields',
			t('If you have any content left in this field, it will be lost. This action cannot be undone.'),
			t('Delete'), t('Cancel'),
			'confirm'
	);

	if ($field['locked']) {
		unset($output['actions']['submit']);
		$output['description']['#markup'] = t('This field is <strong>locked</strong> and cannot be deleted.');
	}

	return $output;
}

/**
 * Form submission handler for field_ui_field_delete_form().
 *
 * Removes a field instance from a bundle. If the field has no more instances,
 * it will be marked as deleted too.
 */
function field_ui_field_delete_form_submit($form, &$form_state) {
	$form_values = $form_state['values'];
	$field_name = $form_values['field_name'];
	$bundle = $form_values['bundle'];
	$entity_type = $form_values['entity_type'];

	$field = field_info_field($field_name);
	$instance = field_info_instance($entity_type, $field_name, $bundle);
	$bundles = field_info_bundles();
	$bundle_label = $bundles[$entity_type][$bundle]['label'];

	if (!empty($bundle) && $field && !$field['locked'] && $form_values['confirm']) {
		field_delete_instance($instance);
		drupal_set_message(t('The field %field has been deleted from the %type content type.', array('%field' => $instance['label'], '%type' => $bundle_label)));
	}
	else {
		drupal_set_message(t('There was a problem removing the %field from the %type content type.', array('%field' => $instance['label'], '%type' => $bundle_label)), 'error');
	}

	$admin_path = _field_ui_bundle_admin_path($entity_type, $bundle);
	$form_state['redirect'] = field_ui_get_destinations(array($admin_path . '/fields'));

	// Fields are purged on cron. However field module prevents disabling modules
	// when field types they provided are used in a field until it is fully
	// purged. In the case that a field has minimal or no content, a single call
	// to field_purge_batch() will remove it from the system. Call this with a
	// low batch limit to avoid administrators having to wait for cron runs when
	// removing instances that meet this criteria.
	field_purge_batch(10);
}

/**
 * Form constructor for the field instance settings form.
 *
 * @see field_ui_field_edit_form_validate()
 * @see field_ui_field_edit_form_submit()
 * @ingroup forms
 */
function field_ui_field_edit_form($form, &$form_state, $instance) {
	$bundle = $instance['bundle'];
	$entity_type = $instance['entity_type'];
	$field = field_info_field($instance['field_name']);

	drupal_set_title($instance['label']);

	$form['#field'] = $field;
	$form['#instance'] = $instance;

	if (!empty($field['locked'])) {
		$form['locked'] = array(
				'#markup' => t('The field %field is locked and cannot be edited.', array('%field' => $instance['label'])),
		);
		return $form;
	}

	$field_type = field_info_field_types($field['type']);
	$widget_type = field_info_widget_types($instance['widget']['type']);
	$bundles = field_info_bundles();

	// Create a form structure for the instance values.
	$form['instance'] = array(
			'#tree' => TRUE,
			'#type' => 'fieldset',
			'#title' => t('%type settings', array('%type' => $bundles[$entity_type][$bundle]['label'])),
			'#description' => t('These settings apply only to the %field field when used in the %type type.', array(
					'%field' => $instance['label'],
					'%type' => $bundles[$entity_type][$bundle]['label'],
			)),
			// Ensure field_ui_field_edit_instance_pre_render() gets called in addition
			// to, not instead of, the #pre_render function(s) needed by all fieldsets.
			'#pre_render' => array_merge(array('field_ui_field_edit_instance_pre_render'), element_info_property('fieldset', '#pre_render', array())),
	);

	// Build the non-configurable instance values.
	$form['instance']['field_name'] = array(
			'#type' => 'value',
			'#value' => $instance['field_name'],
	);
	$form['instance']['entity_type'] = array(
			'#type' => 'value',
			'#value' => $entity_type,
	);
	$form['instance']['bundle'] = array(
			'#type' => 'value',
			'#value' => $bundle,
	);
	$form['instance']['widget']['weight'] = array(
			'#type' => 'value',
			'#value' => !empty($instance['widget']['weight']) ? $instance['widget']['weight'] : 0,
	);

	// Build the configurable instance values.
	$form['instance']['label'] = array(
			'#type' => 'textfield',
			'#title' => t('Label'),
			'#default_value' => !empty($instance['label']) ? $instance['label'] : $field['field_name'],
			'#required' => TRUE,
			'#weight' => -20,
	);
	$form['instance']['required'] = array(
			'#type' => 'checkbox',
			'#title' => t('Required field'),
			'#default_value' => !empty($instance['required']),
			'#weight' => -10,
	);

	$form['instance']['description'] = array(
			'#type' => 'textarea',
			'#title' => t('Help text'),
			'#default_value' => !empty($instance['description']) ? $instance['description'] : '',
			'#rows' => 5,
			'#description' => t('Instructions to present to the user below this field on the editing form.<br />Allowed HTML tags: @tags', array('@tags' => _field_filter_xss_display_allowed_tags())),
			'#weight' => -5,
	);

	// Build the widget component of the instance.
	$form['instance']['widget']['type'] = array(
			'#type' => 'value',
			'#value' => $instance['widget']['type'],
	);
	$form['instance']['widget']['module'] = array(
			'#type' => 'value',
			'#value' => $widget_type['module'],
	);
	$form['instance']['widget']['active'] = array(
			'#type' => 'value',
			'#value' => !empty($field['instance']['widget']['active']) ? 1 : 0,
	);

	// Add additional field instance settings from the field module.
	$additions = module_invoke($field['module'], 'field_instance_settings_form', $field, $instance);
	if (is_array($additions)) {
		$form['instance']['settings'] = $additions;
	}

	// Add additional widget settings from the widget module.
	$additions = module_invoke($widget_type['module'], 'field_widget_settings_form', $field, $instance);
	if (is_array($additions)) {
		$form['instance']['widget']['settings'] = $additions;
		$form['instance']['widget']['active']['#value'] = 1;
	}

	// Add handling for default value if not provided by any other module.
	if (field_behaviors_widget('default value', $instance) == FIELD_BEHAVIOR_DEFAULT && empty($instance['default_value_function'])) {
		$form['instance']['default_value_widget'] = field_ui_default_value_widget($field, $instance, $form, $form_state);
	}

	$has_data = field_has_data($field);
	if ($has_data) {
		$description = '<p>' . t('These settings apply to the %field field everywhere it is used. Because the field already has data, some settings can no longer be changed.', array('%field' => $instance['label'])) . '</p>';
	}
	else {
		$description = '<p>' . t('These settings apply to the %field field everywhere it is used.', array('%field' => $instance['label'])) . '</p>';
	}

	// Create a form structure for the field values.
	$form['field'] = array(
			'#type' => 'fieldset',
			'#title' => t('%field field settings', array('%field' => $instance['label'])),
			'#description' => $description,
			'#tree' => TRUE,
	);

	// Build the configurable field values.
	$description = t('Maximum number of values users can enter for this field.');
	if (field_behaviors_widget('multiple values', $instance) == FIELD_BEHAVIOR_DEFAULT) {
		$description .= '<br/>' . t("'Unlimited' will provide an 'Add more' button so the users can add as many values as they like.");
	}
	$form['field']['cardinality'] = array(
			'#type' => 'select',
			'#title' => t('Number of values'),
			'#options' => array(FIELD_CARDINALITY_UNLIMITED => t('Unlimited')) + drupal_map_assoc(range(1, 10)),
			'#default_value' => $field['cardinality'],
			'#description' => $description,
	);

	// Add additional field type settings. The field type module is
	// responsible for not returning settings that cannot be changed if
	// the field already has data.
	$additions = module_invoke($field['module'], 'field_settings_form', $field, $instance, $has_data);
	if (is_array($additions)) {
		$form['field']['settings'] = $additions;
	}

	$form['actions'] = array('#type' => 'actions');
	$form['actions']['submit'] = array('#type' => 'submit', '#value' => t('Save settings'));
	return $form;
}

/**
 * Pre-render function for field instance settings.
 *
 * Combines the instance, widget, and other settings into a single fieldset so
 * that elements within each group can be shown at different weights as if they
 * all had the same parent.
 */
function field_ui_field_edit_instance_pre_render($element) {
	// Merge the widget settings into the main form.
	if (isset($element['widget']['settings'])) {
		foreach (element_children($element['widget']['settings']) as $key) {
			$element['widget_' . $key] = $element['widget']['settings'][$key];
		}
		unset($element['widget']['settings']);
	}

	// Merge the instance settings into the main form.
	if (isset($element['settings'])) {
		foreach (element_children($element['settings']) as $key) {
			$element['instance_' . $key] = $element['settings'][$key];
		}
		unset($element['settings']);
	}

	return $element;
}

/**
 * Builds the default value fieldset for a given field instance.
 */
function field_ui_default_value_widget($field, $instance, &$form, &$form_state) {
	$field_name = $field['field_name'];

	$element = array(
			'#type' => 'fieldset',
			'#title' => t('Default value'),
			'#collapsible' => FALSE,
			'#tree' => TRUE,
			'#description' => t('The default value for this field, used when creating new content.'),
			// Stick to an empty 'parents' on this form in order not to breaks widgets
			// that do not use field_widget_[field|instance]() and still access
			// $form_state['field'] directly.
			'#parents' => array(),
	);

	// Insert the widget.
	$items = $instance['default_value'];
	$instance['required'] = FALSE;
	$instance['description'] = '';

	// @todo Allow multiple values (requires more work on 'add more' JS handler).
	$element += field_default_form($instance['entity_type'], NULL, $field, $instance, LANGUAGE_NONE, $items, $element, $form_state, 0);

	return $element;
}

/**
 * Form validation handler for field_ui_field_edit_form().
 *
 * @see field_ui_field_edit_form_submit().
 */
function field_ui_field_edit_form_validate($form, &$form_state) {
	// Take the incoming values as the $instance definition, so that the 'default
	// value' gets validated using the instance settings being submitted.
	$instance = $form_state['values']['instance'];
	$field_name = $instance['field_name'];

	if (isset($form['instance']['default_value_widget'])) {
		$element = $form['instance']['default_value_widget'];

		$field_state = field_form_get_state($element['#parents'], $field_name, LANGUAGE_NONE, $form_state);
		$field = $field_state['field'];

		// Extract the 'default value'.
		$items = array();
		field_default_extract_form_values(NULL, NULL, $field, $instance, LANGUAGE_NONE, $items, $element, $form_state);

		// Validate the value and report errors.
		$errors = array();
		$function = $field['module'] . '_field_validate';
		if (function_exists($function)) {
			$function(NULL, NULL, $field, $instance, LANGUAGE_NONE, $items, $errors);
		}
		if (isset($errors[$field_name][LANGUAGE_NONE])) {
			// Store reported errors in $form_state.
			$field_state['errors'] = $errors[$field_name][LANGUAGE_NONE];
			field_form_set_state($element['#parents'], $field_name, LANGUAGE_NONE, $form_state, $field_state);
			// Assign reported errors to the correct form element.
			field_default_form_errors(NULL, NULL, $field, $instance, LANGUAGE_NONE, $items, $element, $form_state);
		}
	}
}

/**
 * Form submission handler for field_ui_field_edit_form().
 *
 * @see field_ui_field_edit_form_validate().
 */
function field_ui_field_edit_form_submit($form, &$form_state) {
	$instance = $form_state['values']['instance'];
	$field = $form_state['values']['field'];

	// Update any field settings that have changed.
	$field_source = field_info_field($instance['field_name']);
	$field = array_merge($field_source, $field);
	try {
		field_update_field($field);
	}
	catch (Exception $e) {
		drupal_set_message(t('Attempt to update field %label failed: %message.', array('%label' => $instance['label'], '%message' => $e->getMessage())), 'error');
		return;
	}

	// Handle the default value.
	if (isset($form['instance']['default_value_widget'])) {
		$element = $form['instance']['default_value_widget'];

		// Extract field values.
		$items = array();
		field_default_extract_form_values(NULL, NULL, $field, $instance, LANGUAGE_NONE, $items, $element, $form_state);
		field_default_submit(NULL, NULL, $field, $instance, LANGUAGE_NONE, $items, $element, $form_state);

		$instance['default_value'] = $items ? $items : NULL;
	}

	// Retrieve the stored instance settings to merge with the incoming values.
	$instance_source = field_read_instance($instance['entity_type'], $instance['field_name'], $instance['bundle']);
	$instance = array_merge($instance_source, $instance);
	field_update_instance($instance);

	drupal_set_message(t('Saved %label configuration.', array('%label' => $instance['label'])));

	$form_state['redirect'] = field_ui_next_destination($instance['entity_type'], $instance['bundle']);
}

/**
 * Extracts next redirect path from an array of multiple destinations.
 *
 * @see field_ui_next_destination()
 */
function field_ui_get_destinations($destinations) {
	$path = array_shift($destinations);
	$options = drupal_parse_url($path);
	if ($destinations) {
		$options['query']['destinations'] = $destinations;
	}
	return array($options['path'], $options);
}

/**
 * Returns the next redirect path in a multipage sequence.
 */
function field_ui_next_destination($entity_type, $bundle) {
	$destinations = !empty($_REQUEST['destinations']) ? $_REQUEST['destinations'] : array();
	if (!empty($destinations)) {
		unset($_REQUEST['destinations']);
		return field_ui_get_destinations($destinations);
	}
	$admin_path = _field_ui_bundle_admin_path($entity_type, $bundle);
	return $admin_path . '/fields';
}
